<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  

  <script>
    // var result    res

    // var result = true && false  // false
    // var result = false && false  // false

    var age = 10

    true && age++

    console.log(age)  //  10


  </script>
</body>
</html>